2. Assuming that the population is normally distributed, construct a 90% confidence interval for the population mean, based on the following sample size of n=5.

1, 2, 3, 4, and 22

In the given data, replace the value 22 with 5 and recalculate the confidence interval. Using these results, describe the effect of an outlier (that is, an extreme value) on the confidence interval, in general.

Find a 90% confidence interval for the population mean, using the formula or technology.

____ ____

(Round to two decimal places as needed.)

In the given data, replace the value 22 with 5.

Find a 90% confidence interval for the population mean, using the formula or technology.

____ ____

(Round to two decimal places as needed.)

Using the results from the previous two steps, what is the effect of an outlier (that is, an extreme value) on the confidence interval, in general?

A.The presence of an outlier in the original data increases the value of the sample mean and greatly decreases the sample standard deviation, narrowing the confidence interval.

B.The presence of an outlier in the original data decreases the value of the sample mean and greatly decreases the sample standard deviation, narrowing the confidence interval.

C. The presence of an outlier in the original data decreases the value of the sample mean and greatly inflates the sample standard deviation, widening the confidence interval.

D. The presence of an outlier in the original data increases the value of the sample mean and greatly inflates the sample standard deviation, widening the confidence interval.

5. According to recent study, 162 of 487 CEOs in a certain country are extremely concerned about Cyber threats, and 71 are extremely concerned about lack of trust in business. Complete parts (a) through (c) below.

a. Construct a 95% confidence interval estimate for the population proportion of CEOs in the country who are extremely concerned about cyber threats.

____ ___

(Round to four decimal places as needed.)

b. Construct a 95% confidence interval estimate for the population proportion of CEOs in the country who are extremely concerned about lack of trust in business.

____ ____

(Round to four decimal places as needed.)

c. Interpret the intervals in (a) and (b). Which of the following is the correct interpretation for the interval in (a)?

A. You can be 95%

confident that the population proportion of the CEOs in the country surveyed who are extremely concerned about cyber threats lies within the interval in (a).

B. You can be 95% confident that the population proportion of all CEOs in the country who are extremely concerned about cyber threats lies within the interval in (a).

C. The population proportion of all CEOs who are extremely concerned about cyber threats lies within the interval in (a) 95% of the time.

D. The population proportion of the CEOs surveyed who are extremely concerned about cyber threats lies within the interval in (a) 95% of the time.

Which of the following is the correct interpretation for the interval in (b)?

A. You can be 95% confident that the population proportion of the CEOs in the country surveyed who are extremely concerned about lack of trust in business lies within the interval in (b).

B. The population proportion of all CEOs in the country who are extremely concerned about lack of trust in business lies within the interval in (b) 95%of the time.

C. You can be 95%

confident that the population proportion of all CEOs in the country who are extremely concerned about lack of trust in business lies within the interval in (b).

D. The population proportion of the CEOs in the country surveyed who are extremely concerned about lack of trust in business lies within the interval in (b) 95% of the time.

10. Suppose that you are going to collect a set of data, either from an entire population or from a random sample taken from that population. Complete parts (a) and (b) below.

a. Which statistical measure would you compute first, the mean or the standard deviation? Explain. Choose the correct answer below.

A. You would compute the standard deviation first because it is needed in order to compute the mean. If you had a sample, you would compute the sample standard deviation. If you had the population standard deviation, you would compute the population mean.

B.You would compute the mean first because it is needed in order to compute the standard deviation. If you had a sample, you would compute the sample mean. If you had the population mean, you would compute the population standard deviation.

C. Both could be computed first because both can be calculated separately.

D. None of the above

b. What does your answer to (a) tell you about the "practicality" of using the confidence interval estimate formula?

A. If you have a sample, you are computing the population standard deviation needed in confidence interval estimate formula. If you have a population and have computed the population mean and population standard deviation, you don't need a confidence interval estimate of the population mean.

B. If you have a sample and a population, you are computing the sample standard deviation, not the population standard deviation needed in confidence interval estimate formula.

C. If you have a sample, you are computing the sample standard deviation needed in confidence interval estimate formula. If you have a population and have computed the population mean and population standard deviation, you don't need a confidence interval estimate of the population mean.

D. None of the above